document.write( "Question 1165063: My question is the sum of seven of the angles of a decagon is 1170.the other three angles are all equal to each other. Calculate the sizes of the other three angles\r
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Algebra.Com's Answer #789513 by Edwin McCravy(20054)\"\" \"About 
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document.write( "The sum of all the angles of an n-sided polygon is (n-2)(180°).\r\n" );
document.write( "A decagon has 10 sides, so\r\n" );
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document.write( "the sum of all the angles of a decagon is (10-2)(180°) = (8)(180°) = 1440°.\r\n" );
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the sum of seven of the angles of a decagon is 1170°.
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document.write( "So the remaining three angles have sum 1440°-1170° = 270°\r\n" );
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document.write( "Since they are equal, they are 270°/3 or 90° each.\r\n" );
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document.write( "Edwin
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